Capsaicin is a vanillyl found in hot peppers and related plants. Capsaicin is a derivative of capsicum oleoresin and capsicum. Capsaicin has been proven clinically effective in controlling pain from rheumatoid arthritis, osteoarthritis, painful diabetic neuropathy and neuralgias such as the pain following shingles (herpes zoster). Capsicum provides relief via localized depletion of substance P, a neuropeptide involved in the transmission of pain impulses from the periphery to the central nervous system.
Capsaicin, capsicum and capsicum oleoresin containing 0.025% to 0.25% capsaicin have been recognized by the FDA as an effective over the counter topical analgesic for the temporary relief of minor aches and pains of muscles and joints associated with arthritis, simple backache, strains, bruises and sprains. However, capsaicin is normally not water-soluble. Capsaicin is soluble in solvents such as alcohol, chloroform, ether or petroleum based products. Therefore, a manufacturer of topical analgesial products containing capsaicin must use a form of oil, grease, chloroform, ether, alcohol or a petroleum type product as their base in order to solubilize the capsaicin and subsequently apply it to the skin.
A problem with using an alcohol, chloroform, or ether based analgesic is these harsh chemicals tend to dry out an individual's skin. In addition, patients may experience a warm stinging or burning sensation at the site of application due to these strong solvents.
A problem with the petroleum based analgesics is that the ointments or creams tend to be extremely greasy to the touch and need to be vigorously rubbed onto the skin in order to be absorbed.